Telegraph system.



No. 782,099. PATENTED FEB. 7, 1905. W. E. ATHEARN.

TELEGRAPH SYSTEM.

APPLICATION rILnn JUNE 2, 19oz.

Patented February '7, 1905.

UNTTED STATES PATENT QEEIcE.

WILLIAM EDTVARD ATHEARN, OF BROOKLYN, N ETY YORK.

TELEGRAPH SYSTEM.

SPECIFICATION forming part of Letters Patent No. 782,099, dated February'7, 1905.

Application filed June 2,1902. Serial No. 109,990.

To MN //'7/ om it may concern:

Be it known that l, VILLIAM EDWARD A'rH- EARN, a citizen of the UnitedStates, and a resident of Brooklyn, in the county of Kings and State ofNew York, have invented a certain new and useful Tlelegraph System, ofwhich the following is a specification.

This invention relates to electric telegraphs; and its object is theemployment of two kinds of currents, the direct and the alternating, forproducing a simple quadruplex system. The object is attained by themeans set forth in this specification and the accompanying diagram,which represents the main features of equipment for terminal stations.

At the ground end of the line L is a source of current, which may be abattery, a generator or generators, as indicated at m m. The leads 1/ ufrom said current source are con nected with the contact-points 6 7 ofthe transmitter T. A key 1, in circuit through line a a a with thebattery )1 and coil of the transmitter, is employed for sending impulsesfrom the generators to the line. A transformer A is inserted in the lineat a point beyond the transmitter T, the secondary 4 of the transformerconstituting a part of the line. The primary 5 of the transformers isconnected, through 1/ u a, with a source of alternating current, whichis here shown to be a generator At, and with the lever and contactpointsof the transmitter-T. This transmitter is operated by key 2 through theline 11 0 which includes a battery 1/. Between the transformer and thefirst transmitter a choke or damming coil C/r is inserted in the mainline L, and between this dannning-coil and the transformer is a line (2from the main line to the earth. This ground-line includes a condenser(1. Beyond the transformer the main line passes through one of the coilsof a polarized relay PR, and a choke-coil C71 is inserted in the linebeyond the relay. A branch w from the main line passes through the othercoil of the polarized relay, through a chokecoil C/r, through theequating-rheostat ER to the earth This polarized relay actuates thesounder B through the contact-point 8, the line 1/ (I, and the battery11 A condenser C is bridged upon line i 2' between the main line and thebranch line c between the polarized relay and the damniing-coils (/1C/t".

From the main line between the transformer and the polarized relay abranch-line is divided and taken to a differential relay R, the mainbranch being connected with one winding of the relay, and the secondbranch to the reverse winding of the relay. From the coils of the relaythe branch is continued to the main line L at a point beyond thechokecoil C/t. The second branch I is connected with the ground-line ebetween the choke-coil /1 and the rheostat ER. Each of the branchesincludes a condenser U C, respectively, between the point of division 9and the relay. The relay It operates the relay-sounder RS through itslever, contact-point 10, line b l/ 7/, and battery 11, and this sounderactuates the reading-sounder S through its lever, contactpoint 11, line6 7) 7;, and battery 1/". Shunting the equating-rheostat ER is a line e,including within it a retarding-rheosfat RR and a condenser Theoperation of the system is as follows: Manipulation of the key 1 willcause the transmitter T to put current impulses of opposite polarityupon the line L. They will pass through the coil /z, through thesecondary of the transformer A, and the branch 1/ being adjusted to anequal resistance with the line L the current will divide equally at thepoint 12 on the main line. One half will follow the line to its terminalstation, and the other half will go to the earth through the line As anequal amount of current passes through each of the coils of thepolarized relay, the relay Will not be affected by it. .\lanipulation ofkey 2 will cause alternating impulses to pass through the transformer A,inducing like impulses upon the main line. The impedance to the passageof these impulses offered by the coil Cit will cause the alternations tofind a path upon the earth-line r, the condenser G offering little or noresistance to them. The

impedance of the coils U/t' (1/1" beyond the polarized relay \villdivert these currents to the easier paths of the branches 1, one portionof the current going upon the line I, through the relay, to the mainline, the other portion going upon the line I, through the relay, to theearth-line e, the condenser 0 and lesser resistance of RR affording thecurrent a preferable path around the greater impedance of ER. Thepassage of these impulses through the relay will have no effect upon it,since the windings of Z is opposed to that of l. 7

It is to be borne in mind that the Morse characters spoken of herein asimpulses are not composed of alternating impulses of a certain or givenpolarity, but that each character is made up of a number of cycles,dependent upon the speed of the generator.

Incoming signals will find paths as follows: A direct current coming inupon the main line L will pass through the coil Ch, through the magnet Pof the polarized relay, and will cause a response of the relay-lever andconsequent action of the sounder S. It will pass on through the coil &of the transformer, will not go to earth through the line 6 because ofthe condenser C, will go through the coil Ch, through thetransmitter-lever and one of its contacts, through the line a, generatoron, and to the ground. Alternating-current signals coming in upon theline will be diverted by the coil Oh to theline Z, will pass through therelay R, causing movement of its lever and consequent action of thesounders RS and S. The current will divide at the point 9, part of itreturning, through the relay, upon the line Z, increasing its firstefiect upon the relay-magnet, the balance of the current finding a paththrough the line-condenser C and C and the circuit etc the ground. Undersome conditions a sufiicient amount of the incoming alternating currentmight penetrate the coil Ch to affect the polarized relay. By means ofthe bridging-line iand the condenser C the possibility of operatingthis.

relay is avoided, as the current would divide itself between the twocoils of the relay.

The direct-current and alternating-current signals are non-interferingwith one another, and the instruments thus adapted to be affected by onekind of impulse will not respond to the others.

It will be observed that this is practically a duplex system convertedinto a quadruplex by the addition of the alternating-current featuresdescribed.

I claim- 1. In a quadruplex telegraph system the combination with a mainline of a source of direct current and such current-transmittingdevices, a damming-coil contiguous to said devices, a ground-lineincluding a condenser adjacent to said coil, a transformer with itssec-= ondary included in the main line adjacent to the said ground-line,a source of alternating current and devices for transmitting saidcurrent impulses through the transformer, a polarized relay with atranslating-sounder next the transformer with one of its coils includedin the main line with a damming-coil adjacent to it, a branch from themain line passing through the other coil of the polarized relay andextending to the ground embracing a damming-coil and anequating-rheostat, another branch from the main line back of thepolarized relay said branch subdivided and passing through adiflerential relay connected with translating-sounders, one of itsbranches united to the main line beyond the last dam ming-coil, theother branch united to the ground-line from the polarized relay, ashuntaround the equating-rheostat embracing a retarding-rheostat and acondenser, and a bridge including a condenser uniting the branches fromthe polarized relay, all substantially as set forth.

2. The combination with a main line and the devices for duplextransmission substantially as herein shown of means for quadruplexingthe system comprising a transformer with its secondary in the line,means for sending Morse signals through the transformer from analternating-current source, a differential relay having a double circuitfrom the main line with condensers in said circuits, one of saidcircuits united to the main line beyond the last damming-coil in theline, and the other circuit united to the duplexing ground-line betweenthe choke-coil and rheostat in said line, a condenser shunted around thetransformer, a condenser in a ground-line adjacent to the transformer, adamming-coil between said ground-line and the duplex transmitter,damming-coils in the main line and duplex ground-line beyond thepolarized relay, and a condenser bridged between the main line andduplex ground-line adjacent to the polarized relay, substantially as setforth.

Signed at New York, in the county of New York and State of New York,this 23d day of May, A. D. 1902.

WILLIAM EDWARD ATHEARN. Witnesses:

JOHN C. SANDERS, RoB'r. H. MoRRIs.

